1. Field of the Invention
The present invention relates to an apparatus for automatically inserting a plug into an end portion of a metal tube and processing the end portion into a pointed configuration, prior to a drawing of the tube using a die and the plug.
2. Prior Art
When a hollow tube is drawn by the use of a die and a plug, the plug is inserted into the tube to a location adjacent to an axial end face thereof, an end portion of the tube is pointed by a pointing device , and the pointed end portion is gripped by a chuck of a drawing apparatus and is caused to pass through the die hole so that an outer diameter of the tube is regulated by the die hole and a wall thickness of the tube is regulated by the plug.
Heretofore, the insertion of the plug into the tube before pointing the end portion thereof has been performed manually. Specifically, an operator slightly dimples, by a hammer, a portion of the tube remote from the axial end face thereof by a predetermined distance to form a first positioning section on the tube, inserts an oil supply nozzle into the tube to supply oil thereinto, manually inserts a plug from the axial end face of the tube to the first positioning section, thereafter, again slightly dimples by the hammer a portion of the tube intermediate the axial end face of the tube and the inserted plug to form a second positioning section on the tube for preventing the inserted plug from coming out of the tube, thereafter, inserts the end portion of the tube into the pointing device to point the end portion of the tube so as to provide a pointed end portion. In the prior art, such plug inserting operation has been entirely performed manually by an operator, except for the pointing operation by the pointing device, and it has been a great strain on the operator.